The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Scroll machines in general, and particularly scroll compressors, are often disposed in a hermetic shell which defines a chamber within which is disposed a working fluid. A partition within the shell often divides the chamber into a discharge pressure zone and a suction pressure zone. In a low-side arrangement, a scroll assembly is located within the suction pressure zone for compressing the working fluid. Generally, these scroll assemblies incorporate a pair of intermeshed spiral wraps, one or both of which are caused to orbit relative to the other so as to define one or more moving chambers which progressively decrease in size as they travel from an outer suction port towards a center discharge port. An electric motor is normally provided which operates to cause this relative orbital movement.
The partition within the shell allows compressed fluid exiting the center discharge port of the scroll assembly to enter the discharge pressure zone within the shell while simultaneously maintaining the integrity between the discharge pressure zone and the suction pressure zone. This function of the partition is normally accomplished by a seal which interacts with the partition and with the scroll member defining the center discharge port.
The discharge pressure zone of the hermetic shell is normally provided with a discharge fluid port which communicates with a refrigeration circuit or some other type of fluid circuit. In a closed system, the opposite end of the fluid circuit is connected with the suction pressure zone of the hermetic shell using a suction fluid port extending through the shell into the suction pressure zone. Thus, the scroll machine receives the working fluid from the suction pressure zone of the hermetic shell, compresses this working fluid in the one or more moving chambers defined by the scroll assembly, and then discharges the compressed working fluid into the discharge pressure zone of the compressor. The compressed working fluid is directed through the discharge port through the fluid circuit and returns to the suction pressure zone of the hermetic shell through the suction port.
Various refrigerants have been utilized in refrigeration systems having a scroll machine. When the scroll machine is used as a compressor in refrigeration, as well as air conditioning and heat pump applications, it is particularly advantageous to operate the scroll machine at the optimum pressure for the refrigerant and refrigeration system. Often times, a scroll machine which is designed for one refrigerant does not operate well for use with other refrigerants due to the different solvent properties of the different refrigerants and due to pressure and operating temperature differences. Additionally, hermetic compressors may pose particular design challenges, as they are typically not disassembled for regular maintenance of internal parts. Thus failure or degradation of certain components can end a hermetic compressor's service life. Accordingly, the present disclosure is directed to a scroll machine which is designed to operate efficiently and to have improved wear resistance when operated with CO2 refrigerant.